1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. In addition, the present invention relates to a process, a machine, manufacture, or a composition of matter. One embodiment of the present invention relates to a semiconductor device, a light-emitting device, a display device, an electronic device, a lighting device, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a light-emitting device using an organic electroluminescence (hereinafter also referred to as EL) phenomenon, and a method for manufacturing the light-emitting device. In particular, one embodiment of the present invention relates to a peeling method and a method for manufacturing a device including a peeling process. Moreover, one embodiment of the present invention relates to a laser irradiation system that can be used for the method for manufacturing the device.
2. Description of the Related Art
In recent years, a flexible device in which a functional element such as a semiconductor element, a display element, or a light-emitting element is provided over a substrate having flexibility (hereinafter also referred to as a flexible substrate) has been developed. Typical examples of the flexible device include, as well as a lighting device and an image display device, a variety of semiconductor circuits including a semiconductor element such as a transistor.
As a method for manufacturing a device including a flexible substrate, a technique has been developed in which a functional element such as a thin film transistor or an organic EL element is formed over a formation substrate (e.g., a glass substrate or a quartz substrate), and then the functional element is transferred to a flexible substrate. This technique needs a step of peeling a layer including the functional element from the formation substrate (also referred to as a peeling step).
For example, Patent Document 1 discloses the following peeling technique using laser ablation: a separation layer formed of amorphous silicon or the like is formed over a substrate, a layer to be peeled which is formed of a thin film element is formed over the separation layer, and the layer to be peeled is bonded to a transfer body with the use of a bonding layer. The separation layer is ablated by laser light irradiation, so that peeling is generated in the separation layer.
In addition, Patent Document 2 discloses a technique in which peeling is conducted by physical force such as human hands. In addition, Patent Document 2 discloses the following peeling technique: a metal layer is formed between a substrate and an oxide layer and peeling is generated at an interface between the oxide layer and the metal layer by utilizing weak bonding at the interface between the oxide layer and the metal layer, so that a layer to be peeled and the substrate are separated from each other.